NUMERICAL STUDY ON FLOW PAST 2D SQUARE CYLINDER BY LARGE-EDDY SIMULATION - COMPARISON BETWEEN 2D AND 3D COMPUTATIONS

The unsteady flowfield past a two-dimensional(2D) square cylinder at R e=1.0 X 10(5) is predicted by Large Eddy Simulation(LES). Results of t wo-dimensional(2D) and three-dimensional(3D) computations are compared with results of previous experiments[1-4]. It is confirmed that the L ES results based on 3D computation correspond very well with the exper imental results, but the LES results based on 2D computation are diffe rent from those based on 3D computation as well as those based on expe riments. Distributions of mean vorticity, vorticity fluctuations and t urbulence terms in the mean vorticity equation are discussed in order to examine structural differences between the results of 2D and 3D LES computations.